Thermometer: know what each type is for and where to buy

During the Covid-19 pandemic, the thermometer became one of the most used first aid items, since fever is one of the main symptoms of the disease caused by the new coronavirus .

Thus, it was inevitable that the search for the item would increase and it would become one of the most sold products by stores and pharmacies.

However, many people at the time of purchase have doubts about which type of thermometer is most suitable and what are the differences between them. Thinking about it, we separated all the information about the thermometers, check it out and learn more:


What is a thermometer?

Thermometers are devices used to measure the temperature of people, animals, objects and environments.

Thermometer is an instrument available in analog or digital version, being used to measure the exact body temperature and, from that, to affirm whether the person has a high temperature or not.

The thermometer is one of the most used devices in the hospital wing by nurses and doctors, considering that it is possible to know if the patient has a fever, a symptom that is associated with several diseases (especially infectious).

In general, the instrument is placed under the armpit or at the entrance to the anus, however, the most modern versions can be used in other parts of the body such as the forehead, mouth, ear or wrist (by touch or approach).

Therefore, what will determine the most suitable location is the material from which the thermometer is made and the instructions provided by the instrument manufacturers.

Still, in addition to use in people, the thermometer can be useful for measuring the temperature of environments, animals, objects and food.

What types of thermometer?

The infrared thermometer is considered the most advanced model available on the market.

There are several models of thermometer marketed, which serve different purposes. However, for personal use the most used ones are usually:


The analog model, also called a mercury thermometer, consists of a transparent glass tube that contains mercury inside it.

This substance is sensitive to heat and, as it is heated, it expands inside the tube until it reaches a certain mark present on the glass, which consequently indicates the person’s body temperature.

Currently, the use of this type of thermometer is no longer indicated due to the damage that can be caused by direct exposure to this substance (even if the amount is small).

Mercury is part of the chemical group of transition metals that when it comes in contact with the skin or eyes causes some symptoms such as redness and itching.

The longer the time of contact with the substance, the greater the changes in metabolism.

As a result, the National Health Surveillance Agency (Anvisa) determined that the manufacture, import and sale of thermometers (and other health equipment) with mercury in their composition be prohibited.


The digital thermometer is a technological device developed to replace that of mercury and offer greater security to those who buy.

In addition, unlike the old model, it can measure the temperature more quickly and accurately, as it contains an electronic sensor at its tip that, when identifying the temperature, instantly transmits digital signals to the LCD screen located on the surface of the device – thus allowing you to know the person’s temperature.

Because of this greater practicality, the digital thermometer is the most used, both for home use and in hospital networks.

In this sense, some available brands are:

  • Solidor Digital Clinical Thermometer ;
  • Digital Thermometer Incoterm Domotherm ;
  • Omron MC-245 Digital Thermometer ;
  • G-Tech Flexible Tip Digital Thermometer ;
  • Care Tech TS-101 Digital Thermometer .


The infrared model, also classified as digital, is an advanced version that uses infrared laser rays (not visible to the naked eye) to measure the temperature.

These rays (considered safe), when they reach the skin, are able to transmit to the screen of the device almost immediately the value of the temperature of the person. Therefore, this is the fastest and most accurate option for this type of device.

There are two types of infrared thermometer that can be purchased, one to be used on the forehead and the other for the ear.

Both are equally safe and practical, so the choice will vary according to the goal of whoever wants to have the model.

Those on the forehead, for example, usually have the advantage of not having to be in direct contact with the person’s body to measure the temperature, making it easier to keep the device sanitized (especially if it is used in public places).

As for the ear, also known as a tympanic or ear thermometer , it is indicated mainly to measure the temperature in children and babies.

Thus, some available devices are:

  • Anu Non-Contact Infrared Thermometer ;
  • Digital Forehead Thermometer G-Tech ;
  • Digital Forehead Omron Thermometer ;
  • Bioland Digital Forehead and Ear Thermometer ;
  • Digital Thermometer Incoterm Infrared Headset .

What is the best thermometer to measure fever?

The choice of the best thermometer will depend on the purpose of use that each person has.

In terms of effectiveness, all thermometers that are regulated and, consequently, have the seal of Inmetro (National Institute of Metrology, Quality and Technology) and Anvisa (National Health Surveillance Agency), can be used. Therefore, the choice will depend on the preference and needs of those who want to buy the item.

For example, people looking to have a temperature measuring device for family use may choose a simpler thermometer (analog or digital), as there is no obstacle or embarrassment in placing the meter anywhere on the body for a while.

Now, those who wish to use the device in a public place, such as hospitals, shops and leisure areas, can opt for the infrared thermometer, which is more practical, checks the temperature more quickly and does not need to come into contact with the body.

Therefore, there is no restriction on the choice of the best thermometer, as long as it is properly regulated by the responsible control bodies. Considering this, each person can choose the option that best fits their needs.

How to use thermometer?

Usually, the different types of thermometer are used as follows:

  • Analog: Before measuring the temperature, it is necessary to check if it is at 0º (or close to it). Then, it should be placed in one of the recommended places (armpit, mouth or anus), wait for about 5 minutes and remove it to know what the value is marked on the tube.
  • Digital: Just turn on the device, confirm that it is at 0º (in some, only the ºC symbol appears) and then position the thermometer in the armpit region (the arm must remain immobile). It must be removed after hearing the beep of the device and, then, check the temperature indicated on the display.
  • Infrared (forehead): To use the infrared thermometer on the forehead, it is necessary to turn on the device, check the value (which must be 0º) and touch (or not, depending on the instructions provided by the manufacturer) in the region. That done, just read the value that will be immediately displayed on the screen.
  • Infrared (ear): First, the tip of the thermometer must be inserted into the ear (as if towards the nose) and turn on the device. Soon after, it will beep indicating that it has already completed the measurement (the value will appear on the screen).

It is important to note that regardless of the thermometer used, it is necessary to clean it after use, with the help of a cotton, cloth or gauze with alcohol. In addition, it is worth emphasizing that it is always necessary to pay attention to the recommendations of each manufacturer.

Can you take a pulse temperature?

In general, it is possible to check someone’s temperature with an infrared digital thermometer on the wrist, without any problem.

However, measuring the temperature by the pulse may show a small variation in the final result, since this region of the body, being at the end, is usually colder.

Thus, to have a more accurate measurement, it is recommended to use this type of thermometer (infrared) in places such as the forehead or ear.

Price and where to buy

Thermometers, regardless of type, can usually be found in pharmacies and some hospital supply stores.

In addition to these locations, it is possible to buy the device on online platforms, such as Consulta Remédios , which allows you to compare values ​​for the same product in different establishments in your region.

Thus, you can buy the best offer and still receive the product right at your home.

As for the values, the thermometer model and the manufacturer are factors that directly influence the final price *, which can vary from R $ 20 to almost R $ 300. Some options are:

  • Incoterm Termomed thermometer ( digital ) – from R $ 26;
  • Incoterm MedFebre thermometer ( digital ) – from R $ 15;
  • Biopress thermometer  ( digital ) – from R $ 15;
  • Bing Zun BZ-R6 thermometer ( infrared ) – from R $ 129;
  • Prime Health thermometer ( infrared ) – from R $ 250;
  • Aiqura thermometer ( infrared ) – from R $ 199.

* Prices consulted in January 2021. Prices may change.

The thermometer, as well as other devices, exams and treatments in the medical field, were only possible due to the work of researchers and institutes that seek daily to offer the best to society. Therefore, it is always important to value them.

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